Sentinel^® 

Sentinel Technology provides an unmatched filtering system to eliminate contamination of lubricant from grime, dirt or water thereby extending seal and bearing life.  Sentinel Technology dramatically reduces contaminate build-up on hub cap windows, allowing for an accurate determination of lube levels.  Sentinel hub caps provide a tamper-proof system for maximum protection and maintenance-free performance improving performance and lowering overall maintenance costs.  Sentinel oil hub caps are series 348 and grease hub caps are 349 series.

Integrated Sentinel hub caps, which are tamper-proof,  integrate the Sentinel features into the window with fewer components and greater wheel end visibility.  Integrated Sentinel hub caps are 356 series for oil and 358 series for grease.

The traditional aluminum series 340 and 343 hub caps provide durability with the trademark red plug to allow venting of the hub cap.  Using cast aluminum for constructing the hub cap body prevents warpage and provides superior durability and heat dissipation properties.  The trucking industry recognizes STEMCO hub caps as the benchmark.      

For grease applications, the 342 series Dirt Exclusion hub caps provide the same 340 casting without a side fill plug, plus a solid window with a sintered metal vent for venting purposes.

To further support grease wheel ends, STEMCO developed the 352 series Solid Aluminum hub caps with a duckbill vent inserted in the face of a solid hub cap.

STEMCO Stamped Steel grease hub caps are manufactured from 14 gage steel and have a protective yellow chromate plating with a clear lacquer coating for additional protection from corrosion.  For synthetic base grease, use the vented 340-5096 version cap.  For petroleum base grease, use the non-vented 340-5097 hub cap.

STEMCO MTIS/PSI hub caps are available in both oil and grease for several popular applications.  The oil hub caps (343-4370, 343-4371 and 343-4372) have a side fill plug and a standard window with oil fill lines.  The grease hub caps (340-4370, 340-4371 and 340-4372) do not have a side fill plug and incorporate a gray opaque window with no markings.  The PSI tee fitting and flapper valve are to be installed in the center of the hub cap and are available from Meritor or PSI as a part of the PSI system.  For more information regarding the PSI System, contact PSI at 210.222.1926.